Flexible permanent magnet and composition



June 1966 E. STEINGROEVER 3, 57,5 6

FLEXIBLE PERMANENT MAGNET AND COMPOSITION Filed March 2, 1961 I VENTOR N Ema/ STEINGROEVER United States Patent Office 3,257,586 Patented June 21, 1966 3 Claims. oi. 317-1ss) The invention relates to magnetic compositions prepared from permanently magnetic powders and a nonmagnetic binder.

Magnetic compositions of this type may be compressed into magnets or processed to instance by cementing.

I have found a particularly simple procedure for the manufacture of permanent magnets which are provided with magnetically soft conducting pieces.

Both parts are first sprayed separately as bands or profiles, or rolled to slabs (sheets), and then joined by rolling upon each other, cementing, pressing together, or similar treatments. The resulting laminated bands or profiles can be directly employed asadhesiv molding strips.

Laminated sheets of substantial width may be divided into such bands. The magnetizing of such adhesive moldings is carried out in an arc form so that the adhering surface has a magnetic north and south pole.

Suitable permanent magnetic materials ar compounds of the type BaO-6Fe O and alloys known under the names Alni and Alnico, which have the following composition:

Alni, Alnico,

-10 Fe balance balance and contain powdered permanently magnetic compositions of the type BaO-Fe O The particles of said magnetic materials are magnetically anisotropic and have the netic value of the material could not be fully utilized.

According to the present invention, such a sheet or slab, is joined to a return piece 2, which has been made similarly to piece 1, but contains soft magnetic iron powder instead of a permanently magnetic powder.

ably increased.

Instead of using BaO-6Fe O particles as permanent SrO-6Fe O and PbO-6Fe O can mixture with each other.

As nonmagnetic binders, any thermoplastic resin such as homopolymers or copolymers or vinyl chloride, polyamides, cellulose acetate, also natural or synthetic rubbers may be used. I prefer to employ polyethylene.

I claim:

References Cited by the Examiner UNITED STATES PATENTS 2,627,097 2/1953 Ellis 3l7159 2,698,917 1/1955 Van Urk et al 317-201 2,797,370 6/1957 Bennett 317-158 2,892,248 6/1959 Weber et al 29l55.6 2,900,344 8/1959 Stuyts et a] 317201 2,932,545 4/1960 Foley 317-201 X 2,959,832 11/1960 Baermann 317-158 2,965,953 12/1960 Baermann 29-155.6

BERNARD A. GILHEANY, Primary Examiner.

SAMUEL BERNSTEIN, JOHN F. BURNS, Examiners.

G. HARRIS, Assistant Examiner. 

1. A FLEXIBLE MAGNETIC MOLDING STRIP COMPRISING A PERMANENTLY MAGNETIC LAYER HAVING OPPOSITE FLAT SURFACES AND CONTAINING MAGNETIC PARTICLES EMBEDDED IN A NON-MAGNETIC BINDER, SAID MAGNETIC PARTICLES BEING MAGNETICALLY ANISOTROPIC AND MAGNETIZED IN A DIRECTION PERPENDICULAR TO SAID SURFACES, AND A SOFT MAGNETIC LAYER INTIMATELY JOINED TO ONE OF SAID SURFACES AND PRESENTING AN UNINTERRUPTED RETURN PATH FOR THE MAGNETIC FLUX WHEN THE OTHER OF SAID FLAT SURFACES IS ADHERED TO A FERROMAGNETIC BASE, SAID SOFT MAGNETIC LAYER CONSISTING ESSENTIALLY OF A NONMAGNETIC BINDER AND IRON PARTICLES DISPERSED THEREIN. 